Cyclodextrin-PEI-Tat Polymer as a Vector for Plasmid DNA Delivery to Placenta Mesenchymal Stem Cells

Non-viral gene delivery to human mesenchymal stem cells: a practical guide towards cell engineering

In recent decades, human mesenchymal stem cells (hMSCs) have gained momentum in the field of cell therapy for treating cartilage and bone injuries. Despite the tri-lineage multipotency, proliferative properties, and potent immunomodulatory effects of hMSCs, their clinical potential is hindered by donor variations, limiting their use in medical settings. To address this challenge, gene delivery technologies have emerged as a promising approach to modulate the phenotype and commitment of hMSCs towards specific cell lineages, thereby enhancing osteochondral repair strategies. This review provides a comprehensive overview of current non-viral gene delivery approaches used to engineer MSCs, highlighting key factors such as the choice of nucleic acid or delivery vector, transfection strategies, and experimental parameters. Additionally, it outlines various protocols and methods for qualitative and quantitative evaluation of their therapeutic potential as a delivery system in osteochondral regenerative applications. In summary, this technical review offers a practical guide for optimizing non-viral systems in osteochondral regenerative approaches. hMSCs constitute a key target population for gene therapy techniques. Nevertheless, there is a long way to go for their translation into clinical treatments. In this review, we remind the most relevant transfection conditions to be optimized, such as the type of nucleic acid or delivery vector, the transfection strategy, and the experimental parameters to accurately evaluate a delivery system. This survey provides a practical guide to optimizing non-viral systems for osteochondral regenerative approaches.

Development of targeted gene delivery system based on liposome and PAMAM dendrimer functionalized with hyaluronic acid and TAT peptide: in vitro and in vivo studies

The development of gene delivery systems is essential to improve their transfection efficiency and cytotoxicity. Combination of lipid and polymeric nanoparticles with the characteristics of both systems have been considered as a next-generation gene delivery platform. In the current study, we designed a novel and efficient targeted gene delivery system based on liposome and PAMAM dendrimer in cancer cells. Two polymeric formulations containing polyamidoamine-TAT (PAMAM-TAT) and PAMAM-TAT-Hyaluronic acid (HA) and two lipopolymeric carriers including PAMAM-TAT-Liposome and PAMAM-TAT-HA-Liposome were complexed with the Enhanced Green Fluorescent Protein (EGFP) plasmid and then evaluated in terms of physicochemical characteristics. The cytotoxicity and transfection efficiency of these synthetized carriers were accomplished against murine colon carcinoma cell line (C26). The biodistribution of polyplexes and lipoployplexes was also evaluated in the C26 tumor bearing mice. The results showed no significant toxicity for all designed nanoparticles (NPs) in C/P4. The highest gene expression was observed using lipopolyplex PAMAM-TAT-HA-Liposome in C/P4 (ratio polymer/DNA; w/w). Biodistribution study demonstrated more aggregation of targeted lipopolyplex in tumor cells than other nanoparticles (NPs). It could be concluded that the developed targeted lipopolymeric complex could serve as promising nanotherapeutic system for gene therapy. This article is protected by copyright. All rights reserved.

ROS-Generating Amine-Functionalized Magnetic Nanoparticles Coupled with Carboxymethyl Chitosan for pH-Responsive Release of Doxorubicin

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Development of Hydrogels with Self-Healing Properties for Delivery of Bioactive Agents

Hydrogels are an important class of soft materials that find use in bioactive agent delivery. Because of their high water content, hydrogels generally show poor mechanical strength. Long-term wear and tear in physiological conditions may lead to damage in the hydrogel structure during the delivery of bioactive agents. This results in burst and uncontrolled agent release. One strategy to solve this problem is to incorporate self-healing properties into a hydrogel so that the hydrogel can heal fractures automatically to restore original mechanical properties. The objectives of this article are to revisit the latest advances in the design of self-healing hydrogel-based carriers and to offer insights into further research to translate these carriers from the laboratory to real applications.

Augmented tumor accumulation and photothermal ablation using gold nanoparticles with a particular cellular entry orientation

Gold nanoparticles with various functionalities have served as potential tools in nanotechnology for tumor ablation. In this work, we seek to design and develop gold nanoparticle with poly(ethylene glycol)-containing dopamine (hereafter termed as AuND), and to synthesize the AuND with one-sided Tat peptide expression (OT@AuND). We demonstrate the tumor cell-targeting ability on the basis of anti-nonspecific cell binding of OT@AuND and determine how the chemically modified gold nanoparticle–based product affects photothermal tumor therapy in vitro and in vivo. The OT@AuND with a particular cellular entry orientation–induced delayed endocytosis, which is advantageous for enhanced permeability and retention effect-based tumor accumulation. This is because the slower cellular interaction of OT@AuND allows it to have the time to be transported to and bind to the tumor site. In tumor cell lines, OT@AuND showed a lower cellular uptake than gold nanoparticles with full-sided Tat peptide expression (FT@AuND) in the early period (after its in vitro and in vivo administration), but the cellular internalization rate of OT@AuND caught up with that of FT@AuND in the late period. Importantly, the delayed cellular internalization feature of OT@AuND resulted in efficient tumor accumulation in tumor-bearing mice, because the time interval provided OT@AuND more chances not to bind to any cells, but to enter tumor cells, leading to selective photothermal tumor ablation. These data suggest that gold nanoparticles with a particular cellular entry orientation can be further explored as a potential photothermal therapeutic agent and as a strategy to treat tumors.

RGD/TAT-functionalized chitosan-graft-PEI-PEG gene nanovector for sustained delivery of NT-3 for potential application in neural regeneration

In this study, we prepared a multifunctional gene delivery nanovector containing a chitosan (CS) backbone and polyethylenimine (PEI) arms with arginine-glycine-aspartate (RGD)/twin-arginine translocation (TAT) conjugated via polyethylene glycol (PEG). Branched PEI, with a molecular weight of 2000 Da, was used to achieve a balance between biocompatibility and transfection efficiency, whereas RGD/TAT peptides were conjugated for enhanced targeting ability and cellular uptake. Synthesis of the copolymers was confirmed by characterizing the chemical structure with ¹H nuclear magnetic resonance and Fourier Transform Infrared Spectroscopy (FTIR). The nanovector was biocompatible with cells and showed excellent capability for DNA condensation; the resulting complexes with DNA were well-formed, and possessed small particle size and reasonable positive charge. Higher gene transfection efficiency, compared to that achieved with PEI (25 kDa), was confirmed in tumor (HeLa cells) and normal cells (293T and NIH 3T3 cells). More importantly, the cells transfected with the chitosan-graft-PEI-PEG/pCMV-EGFP-Ntf3 complex produced sustained neurotrophin-3 with a linear increase in cumulative concentration, which induced neuronal differentiation of neural stem cell and promoted neurite outgrowth. These findings suggested that our multifunctional copolymers might be ideal nanovectors for engineering cells via gene transfection, and could potentially be applied in tumor therapy and regenerative medicine.

STATEMENT OF SIGNIFICANCE

We successfully prepared a multifunctional gene delivery nanovector containing branched PEI with a molecular weight of 2000 Da to balance between biocompatibility and transfection efficiency, and RGD/TAT peptides for enhanced targeting ability and cellular uptake. The well-formed CPPP/DNA complexes of small particle size and reasonable positive charges potentially enhanced gene transfection in both tumor and normal cells. More importantly, the CPPP/pCMV-EGFP-Ntf3 complex-transfected 293T cells could produce sustained NT-3 with a constant ratio, which induced neuron differentiation of NSC and promoted neurite outgrowth. Therefore, our study provided an effective strategy for producing neurotrophins by engineering cells with gene delivery, which deserved wide investigation and potential application in regenerative medicine.

Exploring the role of peptides in polymer-based gene delivery

Polymers are widely studied as non-viral gene vectors because of their strong DNA binding ability, capacity to carry large payload, flexibility of chemical modifications, low immunogenicity, and facile processes for manufacturing. However, high cytotoxicity and low transfection efficiency substantially restrict their application in clinical trials. Incorporating functional peptides is a promising approach to address these issues. Peptides demonstrate various functions in polymer-based gene delivery systems, such as targeting to specific cells, breaching membrane barriers, facilitating DNA condensation and release, and lowering cytotoxicity. In this review, we systematically summarize the role of peptides in polymer-based gene delivery, and elaborate how to rationally design polymer-peptide based gene delivery vectors.

STATEMENT OF SIGNIFICANCE

Polymers are widely studied as non-viral gene vectors, but suffer from high cytotoxicity and low transfection efficiency. Incorporating short, bioactive peptides into polymer-based gene delivery systems can address this issue. Peptides demonstrate various functions in polymer-based gene delivery systems, such as targeting to specific cells, breaching membrane barriers, facilitating DNA condensation and release, and lowering cytotoxicity. In this review, we highlight the peptides' roles in polymer-based gene delivery, and elaborate how to utilize various functional peptides to enhance the transfection efficiency of polymers. The optimized peptide-polymer vectors should be able to alter their structures and functions according to biological microenvironments and utilize inherent intracellular pathways of cells, and consequently overcome the barriers during gene delivery to enhance transfection efficiency.

Smart polymeric nanoparticles for cancer gene delivery

The massive amount of human genetic information already available has accelerated the identification of target genes, making gene and nucleic acid therapy the next generation of medicine. Nanoparticle (NP)-based anticancer gene therapy treatment has received significant interest in this evolving field. Recent advances in vector technology have improved gene transfection efficiencies of nonviral vectors to a level similar to viruses. This review serves as an introduction to surface modifications of NPs based on polymeric structural improvements and target moieties. A discussion regarding the future perspective of multifunctional NPs in cancer therapy is also included.

Aminated β-Cyclodextrin-Modified-Carboxylated Magnetic Cobalt/Nanocellulose Composite for Tumor-Targeted Gene Delivery

Gene therapy is a new kind of medicine, which uses genes as drugs in order to treat life threatening diseases. In the present work, a nonviral vector, aminated β-cyclodextrin-modified-carboxylated magnetic cobalt/nanocellulose composite (ACDC-Co/NCC), was synthesized for efficient transfection of genes into tumour cells. The synthesized ACDC-Co/NCC was characterized by means of FTIR, XRD, SEM, and ESR techniques. DNA condensing ability of ACDC-Co/NCC was found to be increased with increase in amount of ACDC-Co/NCC and 84.9% of DNA (1.0 μg/mL) inclusion was observed with 6.0 μg/mL of ACDC-Co/NCC. The cytotoxicity of ACDC-Co/NCC was observed to be minimal, even at higher concentration, with respect to the model transfecting agent, poly(ethyleneimine) (PEI). 88.2% of the gene was transfected at high dose of DNA, as indicated by the highest luciferase expression. These results indicated that ACDC-Co/NCC might be a promising candidate for gene delivery with the characteristics of good biocompatibility, potential biodegradability, minimal cytotoxicity, and relatively high gene transfection efficiency.

A mannosylated cell-penetrating peptide-graft-polyethylenimine as a gene delivery vector

Polyethylenimine (PEI) is widely applied in non-viral gene delivery vectors. PEI with high molecular weight is highly effective in gene transfection but is high cytotoxic. Conversely, PEI with low molecular weight displays lower cytotoxicity but less delivering efficiency. To overcome this issue, a novel copolymer with mannosylated, a cell-penetrating peptide (CPP), grafting into PEI with molecular weight of 1800 (Man-PEI1800-CPP) were prepared in this study to target antigen-presenting cells (APCs) with mannose receptors and enhance transfection efficiency with grafting CPP. The copolymer was characterized by (1)H NMR and FTIR. Spherical nanoparticles were formed with diameters of about 80-250 nm by mixing the copolymer and DNA at various charge ratios of copolymer/DNA(N/P). Gel retardation assays indicated that Man-PEI1800-CPP polymers efficiently condensed DNA at low N/P ratios. Cytotoxicity studies showed that Man-PEI1800-CPP/DNA complexes maintained in a high percentage of cell viability compared to the PEI with molecular weight of 25 k (PEI25k). Laser scan confocal microscopy and flow cytometry confirmed that Man-PEI1800-CPP/DNA complexes resulted in higher cell uptake efficiency on DC2.4 cells than on Hela cells line. The transfection efficiency of Man-PEI1800-CPP was significantly higher than that of PEI25k on DC2.4 cells. More importantly, the complexes were mainly distributed in the epidermis and dermis of skin and targeted on splenocytes after percutaneous coating based on microneedles in vivo. These results indicated that Man-PEI1800-CPP was a potential APCs targeted of non-virus vector for gene therapy.

Cyclodextrins in non-viral gene delivery

Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides. They consist of (α-1,4)-linked glucose units, and possess a basket-shaped topology with an "inner-outer" amphiphilic character. Over the years, substantial efforts have been undertaken to investigate the possible use of CDs in drug delivery and controlled drug release, yet the potential of CDs in gene delivery has received comparatively less discussion in the literature. In this article, we will first discuss the properties of CDs for gene delivery, followed by a synopsis of the use of CDs in development and modification of non-viral gene carriers. Finally, areas that are noteworthy in CD-based gene delivery will be highlighted for future research. Due to the application prospects of CDs, it is anticipated that CDs will continue to emerge as an important tool for vector development, and will play significant roles in facilitating non-viral gene delivery in the forthcoming decades.

Strategies on the nuclear-targeted delivery of genes

To improve the nuclear-targeted delivery of non-viral vectors, extensive effort has been carried out on the development of smart vectors which could overcome multiple barriers. The nuclear envelope presents a major barrier to transgene delivery. Viruses are capable of crossing the nuclear envelope to efficiently deliver their genome into the nucleus through the specialized protein components. However, non-viral vectors are preferred over viral ones because of the safety concerns associated with the latter. Non-viral delivery systems have been designed to include various types of components to enable nuclear translocation at the periphery of the nucleus. This review summarizes the progress of research regarding nuclear transport mechanisms. "Smart" non-viral vectors that have been modified by peptides and other small molecules are able to facilitate the nuclear translocation and enhance the efficacy of gene expression. The resulting technology may also enhance delivery of other macromolecules to the nucleus.